Device for developing photographic prints



March 30, 1937. A. SCHADE Er AL 2,075,306

navrcwea DEVELOPING Puo'romwrc. muws 2 Sheets-Sheet l March 3o, 1937.2,075,306

DEVICE FOR DEVELOPING PHOTOGRAPHIC PRINTS A. scr-IADE Er AL Filed Oct.4, 1955 2 Sheets-Sheet 2 estema so; i' i931 PATENT. oFFlcE A. 2,015,306mmol: ron. nnvnLormG rno'rocnsrmc ram'rs Arthur Schade and Josef Horn.Wiesbaden-Ble'- assignors to Kalle Co. Ak-

briclx. Germany tlengeselllchalt, Wiesbaden-Biebrich, GermanyApplication October 4. 1935, Serial No. 43,584

lnennany November 8. 1934 v'ltllaima The present invention relates todevices for developing photographic prints.

An object of the present invention is a devicev for the development oiphotographic prints by the aid of gaseous materials which, iorthepurpose oi conveying the prints through the developing space, isprovided with. a relatively large driven roller and a number of smallerrollers, arrangedaround the large roller and lightly pressed up againstthis large roller so that they eect in conjunction with the latter theconveyance of the prints.

f Other objects of the invention are springs, which press the saidpressing rollers resiliently on the driven transport roller.

Further objects of the invention are stationary guiding members arrangedaround the large transport roller preferably at a distance which isgreater than the thickness of the material to be developed, for exampleat a distance of several millimetres. These guiding members prevent anydeviationcf the prints fed between the single pressing rollers andensure a reliable conveyance of the sheets around the transport roller.

Another object of the invention'is a substantially gastight developingchamber, provided with an inlet slit and an outlet slit for introducingand discharging the material to be developed, within which chamber thedescribed conveying system is arranged.

Further objects of the invention are devices for rendering the chamberair-tight. These devices are provided at the inlet slit and the outletslit and cperate in conjunction with the transporting systeni in theinterior ci? the chamber so that on the '3 one hand escape of thedeveloping gas is prevented, and on the other hand reliable introductionand discharge ci the prints is ensured.

Another abject of the invention is a device for the production eradmission of the developing gas. As such device there may be used acontainer arranged in thedeveloping chamber filled with liquid ammoniaand provided with heaters for cvapcratingammonia gas. Other equivalentsources of ammonia gas will be described in the 'speciiicatiom K Furtherobjects of the invention are heating devices, which prevent anycondensation of moisture at the conveying elements and the sheetsrespectively, and effect at the same time an acceleration oi thedevelopment.

Another object of the invention is a degassing device, for instance aventilated chamber, preferably heated, provided at the discharge openingci the developing chamber and directly connected whole of the print.

to the said opening, whereby development, are freed from any developinggas which may be on them.

Another object of the invention is a device for drawing oil anydeveloping gas which may escape y through the inlet opening of thedeveloping cham- Other objects of the invention will be seen in thespecieation following hereinafter.

The new developing machine permits a very eflicient development of thesheets inasmuch as the prints are only touched by the conveying memberson both sides at a few places, while the developing gases have freeaccess to almost the Inasmuch as the prints in their passage from onepressing roller to another pressing roller are also not pressed tightlyup against the conveying roller, the access of gas takes place from bothsides at certain places, Awhereby the developing action is-still furtherirnproved Y The inventionv is illustrated by way of example in theaccompanying drawings, in which:

N Fig. 1 is a sectional end elevation oi a constructional form of adeveloping device according. to the invention, and Fig. 2 is a partialiront sectional elevation thereof. Figs. 3 and 4 show anotherconstructionaliform of a developing device according to the invention.Fig. shows a. constructional ferm of the heaters shown in Figs. 1-4.

Referring to the device shown in Figs. 1 and 2, the developing chamber Iis mounted on the frame 2i. In that chamber, which is filled with thedeveloping gases, in particular ammonia, a relatively large conveyingroller 2 turns which is driven. hy ineens of the motor 29 and thedriving gear Sti. The relier 2 may be prcvdedwith rubber strips on itssurface for ensuring the transpcrt of the prints to be developed..Around the said roller, at a distance of about 4 millimetres, a grid orcage made of strong circularly curved wires 3 is arranged to form aguide passage 4. The wires are attached to the ledges 39, the latterbeing connected with the wall of the developing chamber. Around thelarge roller 2, winch turns on the shaft 33, several radially resilientdise rollers d are arranged the axles 24 of which are slidlngiy'arranged in the slot-bearings 2E. The disc rollers are pressed by theirWeight or by springs il mounted upon ledges Z6 against the large roller.-The disc rollers 5 are so arranged that the single discs passindividually between the wire members 3. The place of entry 22 for theprints is rendered air-tight by means oi a the prints. suer steel-band1, which bears with moderate pressure on the roller 2 and prevents theescape of the developing gases. The steel-band 'I is attached to theledges 40. At the point 23, where the prints emerge, a roller 8 isarranged, which is driven by the driving gear 3l. The external surfaceof the roller 8 is rendered air-tight with regard to the chamber bymeans of the steelband 9, the latter being connected with the casing bymeans of the ledges 4l. The detaching members ill lift the paper oi theroller and direct it into the ventilation passage li, which is limitedon one side by the perforated plate 42. In the passage i l the paper isfreed from the developing gas and thereupon passes into the open air.The developing chamber I is bounded by the external surface of tharoller2 and the covering l2 of the device, which is insulated with regard tothe exterior. Electrical heating elements I3, which heat the developingchamber to the most favorable temperature and prevent the condensationof water on the wires 3 and on the outer surface of the roller 2 arearranged around the roller 2 equidistant from center. The supply ofammonia to the device may be effected, for example, by causing asolution of ammonia to pass drop by drop from a container 28 by means ofsupply pipe i4 to a heated evaporating gutter l5 upon which it isvaporized within the developing chamber. lThe quantity of ammoniasupplied is regulated by 'means of a needle valve i6 and may be observedby means or" the show glass 38. 32 is a discharge tube for dischargingwaste liquid. lit is also possible to supply the ammonia by allowingammonia gas to pass from a steel container into individual tubes il,which are arrangedparallel to the conveying roller 2 and are provided onthe side directed towards the material to be developed with a series ofopenings through which the gas emerges. In this way the web of paperwhich is to be developed is subjected to a uniform blast of developinggas, as a result of which a very strong developing action is attained.The removal of gas from the nished prints is effected on the one hand bythe heating action of the heating elements lil which heat theventilation passage l l, and on the other hand by a current of airiiowing in an opposite direction to the direction of motion of theprints, the said current of air being produced in the chamber 20 and thepassage il by means of a Ventilating ian i9.

In the Figs. 3 and 4 of the drawings another constructional form of adeveloping machine according to the invention similar to that shown inFigs. 1 and 2 is shown. The degassing device is arranged in thisconstruction above the developing chamber l. The latter has a doublecovering l2 which contains in its interior a heat insulating felt layer44. The covering consists of an upper part and a lower part, whichlatter is removably arranged to facilitate repairing in the interior ofthe chamber. A tight connection between the upper and lower parts iseiected by means of a rubber ring 36. In the interior of the developingchamber is arranged a transport roller 2, the shaft 33 of which ismounted in roller bearings 34. The disc rollers 5 are mounted upon thelevers 3l which latter are pivotally arranged on the shafts 35. The freeends of the said levers are connected to one another by means of thesprings 45, so that the disc rollers 5 are resiliently pressed on thetransport roller 2. A screw 43 is provided permitting to regulate thetension of the spring 45.

The other parts of the machine correspond to that of the constructionshown in Figs. 1 and 2.

We claim:

1. A device for gaseous development of light sensitive materialcomprising a developing chamber provided with an opening, a driventransport rollerarranged in the said opening and extending into theinterior of the said chamber, resilient pressing means in combinationwith the edges of the said opening and touching the said transportroller so forming a gastight inlet slit and a gastight outlet slitrespectively for the material to be developed, a series of pressingrollers around the said driven transport roller and resiliently bearingupon that roller, stationary mechanical guiding elements arranged at acertain distance around the said driven transport roller and extendingin the interior of the chamber from the inlet slit to the outlet slit, asource of developing gas in the said chamber, heating elements forheating the interior of the developing chamber, and a degassing chamberadjacent the outlet opening oi the developing chamber.

2. A device for gaseous development of light sensitive materialcomprising a gastight developing chamber, a source of developing gas, aninlet opening and an outlet opening in the said developing chamber, adriven transport roller provided in the said chamber, resilient pressingmembers in conjunction with the said openings and touching the saiddriven roller so causing the material to be developed to be fed into thedeveloping chamber and discharged out of the said chamber without anyescaping of gas, a grating consisting of curved Wires arranged aroundthe said transport roller at a certain distance from the roller whichextends in the interior of the chamber from the inlet opening to theoutlet opening so forming a guiding passage, a series cf disc rollersaround the said driven transport roller passing through the said wiregrating and pressed resiliently against this roller, heating elements inthe said developing chamber, and a degassing chamber adjacent the outletopening of the developing chamber.

3. A device for gaseous development of light sensitive materialcomprising a developing chamber, a source of developing gas and a driventransport roller provided in the said chamber, resilient pressingmembers in conjunction with the walls of the chamber and touching thesaid driven roller so forming a gastight inlet slit and a gastightoutlet slit for the material to be developed, a grating consisting ofcurved wires arranged around the said transport roller at a certaindistance from the roller and extending in the interior of the chamberfrom the inlet slit to the outlet slit, a series of disc rollers aroundthe said driven transport roller passing through the said wire gratingand pressed by means of springaction against this roller, heatingelements in the said developing chamber near the rollers and the guidingelements and a degasslng chamber adjacent the outlet opening of thedeveloping chamber.

4. A device of the class described comprising a developing chamber, asource of developing gas y and a driven transport roller provided in thesaid chamber, a resilient metal band attached to the wall. of thedeveloping chamber and touching the said driven roller so forming agastight inlet slit, a cage consisting 0I curved wires arranged aroundthe said transport roller at a certain distance from the roller formingin the interior of the chamber a guiding passage, which passage isimmediately Joined to the inlet slit. aseries of disc rollers around thesaid driven transport roller passing with their discs through the saidwire cage and pressed by means of spring action against the saidtransportV roller, a driven pressing roller arranged at the end of thesaid passage and touching resiliently the said transport roller soforming a gastlght outlet opening, a metal band attached to the wall ofthe developing chamber and touching the said driven pressing roller soiorming a gastight closure, heating lelements near the rollers and theguiding elements and a degassing chamber adjacent to the said outletopening, the said degassing chamber being in connection with a suctiondevice.

5. A device of the class described comprising a developing chamber, asource of developing gas and a driven transport roller provided in thesaid chamber, a resilient steel band attached to the wall of thedeveloping chamber and touching the said driven roller so forming agastight inlet slit,

a cage consisting of curved wires arranged aroundl the said transportroller at a distance which is larger than the thickness o1' the printsto be developed so forming a guiding passage in the interior or thechamber, which passage is immediately joined to the inlet slit, a seriesoi' disc rollers around the said driven transport roller mounted withtheir axles in slot bearings. passing with their discs through the saidwire cage and pressed by means of spring action against this transportroller, a driven pressingl roller arranged at the end of the saidguiding passage and touching resiliently the said transport roller soforming a gastight outlet opening, a steelband attached to the wall ofthe developing chamber and touching the said driven pressing roller soforming a gastight closure, heating elements near the rollers and theguiding elements and a heated oi the chamber and touching the saiddriven roller so forming a gas-tight inlet slit .and a gas-tight outletslit, for the material to be developed, a

grating consisting of curved wires arranged around the said transportroller .at a certain distance from the roller and4 extending, in theinterior of the chamber, from the inlet slit to the outlet slit, aseries oi disc rollers around the said driven transport roller passingthrough the said wire grating and pressed elastically against thisroller and heating elements in the said developing chamber near therollers and the guiding elements.

7. A device for gaseous development of lightsensitive materialcomprising a developing chamber, a source of developing gas and a driventransport roller provided in the said chamber, resilient pressingmembers in conjunction with the walls of the chamber and touching thesaid driven roller so forming a gas-tight inlet slit and a gastightoutlet slit, for the material to be developed, a grating consisting ofcurved wires arranged around the said transport roller at a certaindistance i'rom the roller and extending, in the interior of the chamber,from the inlet slit to the outlet slit and a series oi disc rollersaround the said driven transport roller passing through the said wiregrating and pressed elasticallyagainst this roller.

` ARTHUR SCHADE.

JOSEF HORN.

